But hasn't HIV treatment always been free in England? Not technically for undocumented migrants and non-United Kingdom citizens. But a new law that went into effect on October 1, 2012, ensures that residents of England living with the virus can't be denied treatment based on their immigration status.

Some migrants living with HIV may still be charged for other forms of care they require, including maternity care, cancer treatment and dialysis.

In addition, the new law only affects fees in England—other U.K. regions may still charge undocumented migrants and non-citizens for HIV treatment. “Scotland, Wales and Northern Ireland can decide independently whether to charge for HIV treatment,” explains the National AIDS Trust (NAT), a leading U.K. advocacy organization. However, NAT notes that “on the whole, HIV treatment charges are not levied or actively pursued in these nations.”

NAT is now calling for a formal change in the law in Scotland, Wales and Northern Ireland “to ensure free universal access to HIV treatment is guaranteed for all across the U.K.”